Guide wire with releasable barb anchor

ABSTRACT

An insertion guide wire with an anchor formed in the distal end for precisely locating a subcutaneous arterial wound and guiding a plug of hemostatic material thereto. When the hemostatic material is properly placed, the anchor can be released and the guide wire removed, leaving no foreign object in the lumen of the artery.

This is a continuation of copending application Ser. No. 08/484,911filed Jun. 7, 1995, which is a continuation-in-part of application Ser.No. 08/182,501 filed Jan. 18, 1994, now abandoned.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to medical devices. More particularly, itrelates to devices used to aid in the insertion of hemostatic materialsinto a wound after completion of a percutaneous procedure. It alsorelates to devices used for precisely locating internal punctures inarteries, veins, internal organs and the like.

Numerous medical procedures involve percutaneous insertions into a veinor artery. Among the more common are cardiac catheterization,intra-aortic balloon pumping (IABP) and percutaneous transluminalcoronary angioplasty (PTCA). When such a procedure is completed, thecatheter and/or sheath is removed, leaving a wound that must berepaired. The wound consists of a skin puncture, an arterial or venouspuncture and a channel through the patient's tissue connecting those twopunctures.

Traditionally, repair was accomplished either by application of pressurefor extended periods of time or sometimes by suturing. More recently ithas been found that insertion of hemostatic materials, especiallycollagen plugs, against the outside wall of the affected artery or veinproduces better results, more rapidly and with less discomfort to thepatient. One such procedure, and a device for practicing that procedure,is described in U.S. Pat. No. 5,391,183, assigned to the assignee ofthis application, the contents of which are incorporated herein byreference.

Since clots within the blood stream are extremely undesirable, it isimportant that the insertion of collagen be done in such fashion as toavoid forcing it through the arterial puncture. Several devices havebeen developed in an attempt to accomplish this objective. For example,U.S. Pat. Nos. 4,744,364, 4,852,568, 4,890,612, to Kensey propose anumbrella-like structure permanently placed in the vessel to seal thearterial wound from the inside. Another approach is described in U.S.Pat. No. 5,108,421 wherein a balloon is placed inside the arteriallumen, expanded until it is larger than the wound, and then pulled backagainst the wall of the artery to act as a temporary seal and stop toprevent further plug advancement.

A different approach to preventing entry of collagen into the artery canbe found in previously noted U.S. Pat. No. 5,391,183. That patentteaches use of a collagen guide sheath which is larger in diameter thanthe vessel puncture. The sheath, because it is oversized, cannot passthrough the vessel puncture so as to enter the lumen. Upon insertion ofsuch a guide sheath, the physician can tell when the distal end reachesthe vessel wall simply by tactile sensation. The collagen, which isinside the sheath, is then held in place at the outer wall of the vesselwhile the sheath is withdrawn.

SUMMARY OF THE INVENTION

The instant invention provides a new and improved system for using anhemostatic plug, generally collagen, to close a percutaneous wound. Sucha plug might act by chemical interaction with the blood or might simplybe a mechanical hemostat that physically blocks the flow of blood, or itmight be a plug that combines these two mechanisms of action. Theinvention permits precise and definitive location of the plug adjacentthe arterial puncture but outside of the arterial lumen and leaves noforeign body in the lumen when the procedure has been completed. Theinvention, however, is not directed to the plug, but rather to a newinsertion guide wire which can be used to facilitate insertion of suchplugs and which can be used for other purposes as well.

In its simplest form, the instant invention involves the use of aninsertion guide wire which has a releasable anchor at its distal end.During insertion, according to the preferred procedure, the anchor ispassed through the introducer sheath used during the percutaneousprocedure. This original introducer sheath will be referred tohereinafter as the "procedural sheath". Upon exiting from the distal endof the procedural sheath, the anchor is within the arterial lumen. Asthe procedural sheath is then withdrawn, the insertion guide wire ispartially retracted until the anchor catches on the inside wall of theartery at the puncture. The anchor prevents complete retraction of theinsertion guide wire. The collagen or other hemostatic material can thenbe passed over the insertion wire directly to the vessel exterior at thepuncture site.

Another feature of the anchor is that it permits precise determinationof the location of the vessel puncture. By use of a reference markplaced at a known distance from the anchor, the location of the vesselpuncture is always known, irrespective of movement of the patient andirrespective of pressure applied in the vicinity of the insertion site.

In the preferred method of practicing the instant invention, after theprocedural sheath is withdrawn, a guide sheath/dilator set is passedover the insertion guide wire until the distal tip of the guide sheathis just outside of the arterial puncture. The dilator is then removedand an insertion tube or canister, preloaded with collagen, is slid downinto the proximal end of the guide sheath. A plunger is then used toforce the collagen plug from the preloaded canister into and through theguide sheath. When the collagen reaches the exterior of the artery wall,its distal end is slightly compressed. In this condition the physicianholds it in place with the plunger, and withdraws the guide sheath,thereby exposing the rest of the collagen to the blood from the arteryand the surrounding tissue. Then, while still holding the collagen inplace, the anchor is released and the insertion guide wire removed,leaving no foreign body inside the arterial lumen. The collagen remainsoutside the artery to seal the puncture.

While it is anticipated that the most immediate and widespread use ofthe present invention will be in connection with sealing percutaneouswounds in femoral arteries, it has many other applications as well. Forexample, the blood vessel being sealed need not be the femoral arteryor, for that matter, any artery at all. It could just as well be a vein.Also, it need not be used only in situations where sealing is required.Rather, it can be used merely for its ability to provide a preciselocation of any internal puncture. It could find utility in connectionwith locating and/or sealing punctures in internal organs, perhaps as anadjunct to laparoscopy. Accordingly, the term "artery" is used herein ina very broad sense to encompass arteries, veins, internal organs and thelike.

Disclosed herein are three basic types of releasable anchors. The firstis a loop anchor which is formed by turning the distal tip of theinsertion wire back upon itself so as to cross the main body of thewire, with the distal tip then forming a pig tail. The second type ofanchor is formed by use of a soft-tipped barb that protrudes from theinsertion wire sheath slightly proximal to the distal end. The thirdtype of releasable anchor according to the present invention iscomprised of an elongated overlapping loop at the distal end wherein theoverlapping loop sections are comprised of interleaved coils. Describedbelow are all three embodiments as well as several alternative versionsthereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an anchor loop insertion wire comprised of a core wire andsheath suitable for use in practicing the instant invention.

FIG. 2 shows the insertion wire of FIG. 1 with its distal end formedinto a loop.

FIG. 3 shows the insertion wire of FIG. 2 with the loop portion thereofwithin the confines of an insertion funnel.

FIG. 4 shows the loop and funnel assembly of FIG. 3 inserted into theproximal end of a procedural sheath.

FIG. 5 shows the insertion wire having been passed through the funnel,through the procedural sheath and into an artery.

FIG. 6 shows the insertion wire in a percutaneous wound, after removalof the procedural sheath with the wire having been partially withdrawnso that the loop anchor engages the inside of the artery wall.

FIG. 7 shows the insertion wire as in FIG. 6 with a guide sheath/dilatorset having been slid down over the wire into the wound.

FIG. 8 is an exploded view of the proximal end of the dilator whenproperly seated in the wound.

FIG. 9 shows the insertion wire and guide sheath as in FIG. 8 with thedilator having been removed.

FIG. 10 shows a collagen cartridge and plunger assembly seated in theproximal end of the guide sheath.

FIG. 11 shows, in cross-section, the assembled and fully chargedcollagen cartridge.

FIG. 12 shows, in cross-section, the insertion guide wire being fed intothe distal end of the collagen cartridge.

FIG. 13 shows, in cross-section, the collagen cartridge of FIG. 11 afterthe split halves of the retaining cone have been ejected.

FIG. 14 shows the collagen plug of FIG. 10 having been pushed by theplunger through the guide sheath and the guide sheath having beenwithdrawn from the wound.

FIG. 15 is an exploded view of the proximal end of the plunger when thecollagen plug is properly seated in the wound.

FIG. 16 shows the core wire of the insertion wire having been partiallywithdrawn so as to release the loop at the distal end.

FIG. 17 shows the insertion wire having been removed while the guidesheath, plunger and collagen plug are held in place.

FIG. 18 shows the wound with the collagen plug in place after theplunger and guide sheath have been withdrawn.

FIG. 19 shows another embodiment of an insertion wire formed into asomewhat different kind of anchor loop.

FIG. 20 shows the anchor loop of the embodiment of FIG. 19 inside anartery.

FIG. 21 shows the anchor loop of FIG. 20 with the core wire withdrawn.

FIG. 22 shows yet another embodiment of an insertion wire formed intostill a different kind of anchor loop.

FIG. 23 shows the anchor loop of FIG. 22 inside an artery.

FIG. 24 shows the insertion wire of FIG. 23 after the anchor loop hasbeen released.

FIG. 25 shows another alternative embodiment of an insertion wire formedinto an anchor loop.

FIG. 26 is yet one more alternative embodiment of an insertion wireformed into an anchor loop.

FIG. 27 is an exploded view, in cross-section, of the loop portion ofinsertion wire depicted in FIG. 26.

FIG. 28 shows the distal portion of an insertion wire with a barb-likeanchor according to the present invention, with the anchor barbextended.

FIG. 29 shows the proximal portion of the insertion wire of FIG. 28.

FIG. 30 shows the core wire of the insertion guide wire having beenmoved distally relative to the core wire sheath to retract the barb.

FIG. 31 shows the distal portion of a second version of the barb anchorinsertion wire embodiment.

FIG. 32 is a cross sectional view taken along line A--A of FIG. 33, ofthe distal portion of a third version of the barb anchor insertion guidewire embodiment.

FIG. 33 is a cross sectional view taken along line B--B of FIG. 32.

FIG. 34 is a cross sectional view taken along line C--C of FIG. 33 withthe core wire removed.

FIG. 35 is a cross sectional view taken along line E--E of FIG. 36 ofthe distal portion of a fourth version of a barb anchor insertion guidewire embodiment.

FIG. 36 is a cross sectional view taken along line D--D of FIG. 35.

FIG. 37 is a cross sectional view taken along line F--F of FIG. 36 withthe core wire removed.

FIG. 38 is a cross sectional view of the distal portion of aninterlocking coil loop anchor insertion guide wire according to thepresent invention in the process of being assembled.

FIG. 39 is a plan view of a locking core wire for use in the insertionguide wire of FIG. 38.

FIG. 40 is a cross sectional view of the distal portion of the insertionguide wire of FIG. 38 fully assembled with the locking core wire inplace.

FIG. 41 is a plan view of the insertion guide wire of FIG. 40.

FIG. 42 is cross sectional view taken along cutting line G--G of FIG.40.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is depicted an insertion wire 10 comprised ofa core wire 12 slidably encased within a core wire sheath 14. The distalend 22 of insertion wire 10 may be provided with a J-tip 16. About twoand a quarter inches or so proximal of J-tip 16, sheath 14 has beenslit, perhaps only for a distance of between 1/8" and 1/4". At the slit,the sheath can be caused to buckle or form a bulge or notch 18 leaving agap 20 between the core wire 12 and the slit portion of the sheath whichforms notch 18.

The core wire 12 and sheath 14 should be made of biocompatiblematerials. For example, the wire may be of a nickel titanium alloy andthe sheath may be polyethylene. The sheath may also be formed of a metalcoil. It has been found that to pass through a 8 Fr. introducer, wiresheath 14 can have an o.d. of about 0.030" and an i.d. of 0.015", whilethe core wire can have an o.d. of between 0.010" and 0.012".

The distal tip of the insertion wire is then bent back and insertedthrough gap 20, forming an anchor loop 24. In this configuration, asbest seen in FIG. 2, the distal end 22 of insertion wire 10 and J-tip16, both of which have passed through gap 20, together act as a pigtail26, protruding sideways from insertion wire 10 with a component normalto the major axis of the insertion wire. Once tip 16 has passed throughgap 20 and the force causing bulge 18 has been released, the bent backportion of insertion wire 10 is held by friction in gap 20, between corewire 12 and sheath 14.

In FIG. 2 it can be seen that sheath 14 is provided with a referencemark 28. This reference mark is at a predetermined distance D from notch18.

In preparation for use, anchor loop 24 is placed within a funnel 30 andthe nose or small end 32 of the funnel is slid into the proximal end 34of procedural sheath 36. The nose of funnel 30 is made long enough so asto pass through hemostatic valve 38 when the cone seats on the proximalend of the sheath. Although the size of funnel 30 is not critical, itslength, taper and cross-section should be such as to permit slidingpassage through proximal end 34 of procedural sheath 36 and throughvalve 38. If desired, the funnel can be provided with its own hemostaticvalve (not shown) to act as a back-up when the nose penetrates the valvein the hub of the procedural sheath.

As noted above, the insertion guide wire 10 of this invention isdesigned, inter alia, for use following the completion of a percutaneousprocedure. Normally, after the operative portion of such a procedure hasbeen completed, the procedure device, for example, the PTCA catheter, isremoved, leaving the procedural sheath 36 in place (as best seen inFIGS. 4 and 5). At this point, the distal tip 40 of the proceduralsheath is still in the lumen 42 of vessel 44, while the body ofprocedural sheath 36 passes through wound channel 46 in the patient'ssubcutaneous tissue 48 and out through skin puncture 50. The insertionguide wire 10 is then pushed, in the direction of arrow A, until theanchor loop 24 and pigtail 26 have exited from distal tip 40 of sheath36 into lumen 42 of artery 44.

With the procedural sheath in place, digital pressure P is applied toartery 44 upstream of puncture 52 and procedural sheath 36 is thenwithdrawn. Because insertion wire 10 passes through hemostatic valve 38,as procedural sheath 36 is being withdrawn, it tends to drag insertionwire 10 along with it. Wire 10 is retracted, either by the draggingaction of hemostatic value 38 or, failing that, by the operator, untilanchor loop 24 and pigtail 26 catch on the inside of the artery wall(see FIG. 6). Anchor loop 24 catches on one side of arterial puncture 52and pigtail 26 catches on the other side, preventing further withdrawalof the insertion wire. Continued withdrawal of the procedural sheathcauses the hemostatic valve 38 to slide over insertion wire 10 until theentire procedural sheath has been removed from the wound, leaving onlythe distal portion of insertion wire 10 in lumen 42 of artery 44. Theremainder of insertion wire 10 runs from there, through arterialpuncture 52, through tissue channel 46 and out through skin puncture 50.

As can be seen, when insertion wire 10 is pulled back so that anchorloop 24 and pigtail 26 impinge on the inside of the wall of artery 44,notch 18 is at arterial puncture 52 and reference mark 28 is, therefore,at distance D, a predetermined known distance from puncture 52.

While maintaining slight tension T on wire 10, a guide sheath 54/dilator56 set is slid down, in the direction of arrows C, over insertion wire10 until reference mark 28 can be seen emerging from the proximal end 64of dilator 56. Although shown as a single stripe, other configurationsmay also be used. For example, the reference mark 28 may actually bemade up of several, axially displaced stripes of different colors ordifferent thicknesses or different darknesses or different separationsor the like, to warn the physician that the distal-most portion of thereference mark is approaching.

Sheath 54 is provided with handle 58 and dilator 56 is equipped withfinger wings 60. To assemble the integrated sheath/dilator set, dilator56 is slid down into sheath 54 until finger wings 60 abut the proximalend of handle 58. Dilator 56 is then turned 1/4 turn to the right tolock the dilator and sheath together as an integrated unit. When theyare locked together, finger wings 60 and handle 58 are aligned, therebyforming a combined handle for the set.

Once reference mark 28 emerges from the proximal end 64 of dilator 56,the sheath is fully inserted. In this position, the physician can beconfident that distal tip 62 of guide sheath 54 is adjacent but outsideof arterial puncture 52 because the sheath/dilator set has been selectedso that the distance from the proximal end 64 of dilator 56 to distaltip 62 of guide sheath 54 is slightly less than distance D. If, astaught in U.S. Pat. No. 5,391,183, an oversized sheath/dilator set isused, when the distal tip of the dilator reaches the wall of the artery,not only will the appearance of reference mark 28 tell the physician tostop, so too will the tactile sensation which is experienced when theoversized dilator impinges against the outside wall of artery 44.

With the sheath thus properly located, and while still maintainingtension T on insertion wire 10, dilator 56 is rotated 1/4 turn to theleft to unlock it from sheath 54 and finger wings 60 are used towithdraw dilator 56. During withdrawal of dilator 56 and thereafter,handle 58 is used to hold sheath 54 in place. To assist in keepingsheath 54 in place, a second reference mark 28' may be placed on wire10.

A canister or insertion tube 66, preloaded with a collagen plug 68 isprovided with a plunger 72, which has an enlarged head 74 at itsproximal end, a stem 73 and a piston 75 at its distal end. Plug 68 ispreferably made with a through lumen 67 in which is seated plugthreading tube 69. At its proximal end 71, tube 69 is sealed. In orderto facilitate insertion of the proximal end of wire 10 into the lumen ofthe collagen plug, an inverted cone 86, split into two halves 86' and86", is fitted into the distal end of the canister (see FIG. 11). Cone86 provides a wide-mouth opening which leads the proximal end of wire 10directly into the lumen of the collagen plug (FIG. 12). Once cone 86 hasserved its purpose, a slight flick of the finger dislodges it from thecanister, permitting the two halves 86' and 86" to separate and fallaway (FIG. 13).

After the proximal end of wire 10 has properly entered tube 69, wire 10is pushed proximally through plug 68. Because the proximal end 71 oftube 69 is sealed, as the proximal end of wire 10 is pushed through andout of plug 68, it carries tube 69 with it (FIG. 13).

Canister 66 is then slid down over insertion wire 10 and into handle 58until stop collar 70 seats against the proximal end of handle 58.Plunger 72, also having a through lumen 76, is then used to force plug68 from canister 66 into guide sheath 54 and through sheath 54 to itsdistal tip 62. When plunger 72 is fully inserted (see FIG. 14), enlargedhead 74 seats against the proximal face of stop collar 70. The length ofthe plunger is chosen so that when head 74 is seated against stop collar70, the distal face 77 of piston 75 is slightly distal to tip 62 ofsheath 54.

In addition, the plunger/collagen plug combination is chosen so that thedistance from the proximal face of head 74 to the distal face 78 ofcollagen plug 68 is equal to or just slightly less than the length ofdilator 56. Therefore, as plunger 72 is pushing plug 68 through guidesheath 54, when reference mark 28 emerges from plunger head 74 (see FIG.15), the physician knows that the collagen plug is adjacent, but outsideof arterial puncture 52.

It should also be noted that anchor loop 24 and pigtail 26 also helpinsure that the collagen stays outside of the artery. Together, loop 24and pigtail 26 act as a physical barrier across puncture 52.

Thereafter, while holding plunger 72 steady, pressure is applied tohandle 58 in the direction of arrows W. This causes the sheath 54 to bewithdrawn from around the collagen plug, leaving the collagen plug toseal arterial puncture 52 and fill wound channel 46. After waiting forapproximately 30 to 60 seconds to permit the collagen to begin reactingwith the blood, pressure P can be removed from the artery.

As noted earlier, insertion wire 10 is comprised of a core wire 12 and asheath 14. Sheath 14, in addition to having a slit near the distal end,has a circumferential cut 80 toward its proximal end 82. Core wire 12 isslidable within the medial portion of sheath 14 from cut 80 to tip 16.However, the portion of sheath 14 which is proximal of cut 80 is affixedto wire 12. This can be accomplished by any number of means, forexample, by use of adhesives, by crimping or other mechanical means orby shrink fitting. Therefore, wire 12 can be made to slide axiallywithin sheath 14 by pushing or pulling on end 82 while holding themedial portion of sheath 14 steady.

After guide sheath 54 has been withdrawn, while holding wire sheath 14in one hand, proximal end 82 is pulled axially in the direction of arrowR. This causes core wire 12 to slide through sheath 14 until its distaltip is proximal of notch 18, thus releasing loop 24, permitting thedistal end of sheath 14 to become flaccid (see FIG. 16) and enablingsheath 14 to be withdrawn entirely from collagen plug 68 (see FIG. 17).The guide sheath 54/canister 66/plunger 72 assembly can then be removedand discarded, leaving only the collagen plug in place, as seen in FIG.18.

While it is believed preferable to "lock" loop 24 in place by passingend 22 through gap 20, in some cases this may not be necessary.Insertion wire 10 may be provided with a pre-formed loop (not shown)near its distal end. This preformed loop may take any one of a multitudeof different shapes. Release of the insertion wire with a pre-formedloop is accomplished simply by pulling on the proximal end of insertionwire 10. The preformed loop, which at this point is in the arteriallumen, straightens out and passes through collagen plug 68.

FIG. 19 shows a somewhat different form of anchor loop configuration. Inthis version, an intermediate portion of core wire 12, near its distalend, has been pulled out of the slit to form loop 84. However, in thisconfiguration there is no bending back of end 22 so as to pass through anotch. Pulling an intermediate portion of wire 12 out through the slitcauses sheath 14 to form angle θ less than about 180° at the slit. Whenthis configuration is used, loop 84 catches on one side of the arterialpuncture and end 22 catches on the other side, as shown in FIG. 20.

Although the manner of forming the loop in FIG. 19 is somewhat differentfrom that of the first version, the end result is substantially thesame. The guide wire is placed in a funnel, inserted through aprocedural sheath into the artery and then pulled back until the loop 84and end 22 catch and act as an anchor. To release the anchor of the FIG.19 embodiment, the core wire 12 is pulled in the direction of arrow R.This causes loop 84 to get smaller and smaller until that section of thecore wire reenters the slit (see FIG. 21) permitting easy withdrawal ofwire 10.

Yet another version of an anchor loop configuration is depicted in FIG.22. In this version, core wire 12 does not reach all the way to thedistal end of insertion wire 10. Instead, it ends short of the distalend and a second core wire, 12' extends from the distal end proximallytoward the main core wire. Since a space can be (but is not necessarily)left between the ends of wires 12 and 12', this embodiment permits asharper bend than the prior embodiments without putting a kink in wire12 that might prevent its withdrawal. This embodiment, therefore, mightprove to be useful for insertion through small diameter introducersheaths.

In the FIG. 22 version, end 22 is passed through notch 18 to make acomplete circle or oval. When inserted through the procedural sheath,one portion of the oval or circle catches on one side of puncture 52 andthe opposite portion catches on the other side, as shown in FIG. 23.

To release the anchor loop of this version, one simply pulls on theproximal end of core wire 12 while holding sheath 14 steady. This causesthe distal tip of core wire 12 to move proximally until it no longerbridges notch 18. There is then nothing to hold loop 24' in any sort ofloop configuration. Instead, it is free to straighten out as insertionwire 10 is withdrawn further, passing through and out of collagen plug68. Notice, in this embodiment, the distal segment 12' of the core wireremains within sheath 14 and when the latter is withdrawn, wire 12'comes out with it.

As those skilled in the art will recognize, guide wires are oftenconstructed of a core wire and a ribbon wire, with both being encasedwithin a wire coil sheath. If a guide wire of this type were used tofabricate, for example, the embodiment of FIG. 22, the core wire wouldbe divided into two pieces 12 and 12', but the ribbon wire (not shown)and the surrounding coil (not shown), which would remain intact, wouldbridge the gap between the ends of wire 12 and 12'. The two ends ofwires 12 and 12' could then be soldered to the ribbon wire and orsurrounding coil for additional stability.

An insertion wire of this structure could be used to practice theinstant invention, for example, by having the ribbon wire andsurrounding coil, in the region of the gap between core wire segments 12and 12', preformed into a loop. This loop, once inside arterial lumen42, would then act as the anchor, and release of this preformed loopanchor would be accomplished by pulling on the proximal end of insertionwire 10. Such a pull would cause the loop to straighten out therebypermitting easy passage through the lumen of collagen plug 68.

Alternatively, this structure could be used in the practice of thepresent invention without any preformed loop. Because wound channel 46is at an angle to the lumen 42 of the artery 44, the stiffness of thebody of the insertion wire causes that wire to assume the configurationof a gentle curve as it transitions from lumen 42 to wound channel 46.However, as the insertion wire 10 is slowly withdrawn, the distal tip ofcore wire segment 12 eventually reaches arterial puncture 52, whereuponthe stiffness is significantly reduced because of the discontinuitybetween wires 12 and 12'. The insertion wire, therefore, can then makean abrupt transition by bending sharply, rather than curving gently.This rather sudden change from a gentle curve to a sharp bend would befelt by the physician. The sharp bend and the distal end 22 extending atan angle to the main axis of insertion wire 10 would then function asthe anchor. This anchor configuration too would be released simply bypulling, with additional force, on the proximal end of insertion wire10.

FIG. 25 depicts another version of the loop anchor intended especiallyfor passage through small (5 or 6 Fr) procedural sheaths. In thisembodiment a short (generally less than about 0.3 inch) stainless steelcannula 88 is fitted into sheath 14. Sheath 14 is circumferentiallysplit near its distal end and cannula 88 is inserted between the twoportions of the sheath. The cannula can be affixed to the two pieces ofsheath 14 using conventional techniques, for example, commenting,crimping, shrink fitting or the like.

As can be seen in FIG. 25, the two ends of sheath 14 do not abut.Instead, a space 90 is left between them. That space, which is bridgedby cannula 88, is retained in gap 20 by virtue of shoulders 92 and 94formed by the two ends of sheath 14.

Alternatively, cannula 88 can be placed inside sheath 14 withoutseparating the sheath into two pieces. In this case, cuts (not shown)could be made in the top part of the sheath overlying cannula 88 andthose cuts would then act as the shoulders to help keep the cannula inthe notch.

It should be noted that core wire 12 need not have identical physicalproperties over its entire length. For example, over most of its length,where pushability is important but bendability is not, it may be maderelatively stiff. This could be accomplished, for example, by using arelatively large diameter wire.

Conversely, at the distal end, pushability is of much less importancebut thinness and bendability are of much greater concern. Therefore, amuch thinner gauge wire can be used toward the distal end than is usedover most of the body length of the insertion wire. In order to use aparticularly thin and flexible wire through the bend of loop 24 and yetnot have it so flexible and flaccid that it will fold over at notch 18and pull through puncture 52, cannula 88 can be used as a reinforcingelement. Ideally, when using this version, cannula 88 would bridgepuncture 52 when loop 24 and pigtail 26 impinge on the inside of theartery wall.

As used herein the term "bendability" refers to the capability of thecore wire to bend easily through a large angle without kinking or takinga permanent deformation or set of such magnitude as would prevent itseasy withdrawal through sheath 14. The smaller the radius of bend a wirecan take without kinking, the greater its bendability.

Yet another version of the loop anchor is shown in FIGS. 26 and 27. Inthis version, core wire 12 is ground down from diameter d, the diameterof the main body of the core wire, to diameter d', the diameter in theregion where the radius of curvature of the bend is smallest. In thisway, the core wire at the bend of loop 24 can be made thinner, moreflexible and less liable to kink when bent to a small radius than istrue of the main body of the core wire. In other words, by grinding itdown the bendability is increased.

In order that the core wire in the bend have enough stiffness to openthe loop up and force the pigtail out at an angle to the main axis ofthe insertion wire when the anchor loop emerges from the proceduralsheath into the artery, a spring winding 96 may be wrapped around theground down portion of the core wire. Winding 96 will not significantlyinterfere with the bendability of core wire 12 around the bend duringpassage through a small diameter (5 or 6 Fr) introducer or proceduralsheath, but will add springability to open the loop 24 and force thepigtail 26 out at an angle when they emerge from the distal end of theprocedural sheath into the arterial lumen.

It should be noted that the sheath/dilator set andcanister/collagen/plunger set could be combined. Thus, the body of thecanister could be made the length of the sheath, with the collagen andplunger pre-loaded therein so that the collagen is near the distal end.The distal tip of the canister sheath could be collapsed inwardly toprovide a blunt nose, with radial cuts therein to permit passagetherethrough of the collagen plug. This pre-loaded canister sheathcombination would be slid down over the insertion wire 10 as describedpreviously.

Although it is believed preferable to remove the procedural sheath andreplace it with a guide sheath, the insertion guide wire of the presentinvention can also be used without a separate guide sheath. For example,it can be inserted directly into the procedural sheath. The proceduralsheath can be provided with a marking (not shown) at a predetermineddistance from its distal tip. After insertion of the anchor loop intothe artery, the procedural sheath can be cut at its mark and thenwithdrawn until its cut end reaches reference mark 28 on insertion wire10. At this point the distal tip 40 of procedural sheath has exited fromlumen 42 of artery 44 and is adjacent puncture 52. The physician canthen proceed as previously described.

Alternatively, the full length procedural sheath could be used. Ofcourse, then plunger 72 would have to be made extra long so that itcould push the collagen plug through the entire length of the proceduralsheath.

The insertion wire of the present invention might also be used withoutthe aid of any guide sheath at all. In that case, the collagen plugwould be slid down over the insertion wire, through wound channel 46until reference mark 28 indicates that the distal end of the collagen isadjacent to puncture 52 but is outside of artery 44.

A second embodiment of an insertion guide wire with releasable anchor isshown in FIGS. 28-37. In this embodiment, the anchor is formed by use ofa protruding barb. Referring to FIG. 28, there is depicted an insertionguide wire 210 comprised of a core wire 212 slidably enclosed within acore wire sheath 214. In this embodiment, the core wire sheath iscomprised of a wire coil 222 of a conventional guide wire. Although notnecessary, the distal end 218 of sheath 214 may be provided with a J-tip(not shown). At least about 13/4 inches and preferably about 31/2 inchesproximal of tip 216, sheath 214 has been provided with a notch or slit220. This notch or slit 220 may be formed by brazing the coils 222together in the region of notch 220 and then machining the slit into thebrazed coils.

In addition to core wire 212 sheath 214 is provided with a safety wire224 as is common in guide wires. Safety wire 224 is employed to providesupport to the insertion guide wire 210. Core wire 212, which providesadditional support to the guide wire, is tapered at its distal end 226.Attached to core wire 212, proximal to distal end 226, is the distal end230 of wire barb 228. The proximal end of barb 228 is provided with a Jtip 234. As can be seen in FIG. 28, distal end 230 of barb 228 is withinlumen 248 in sheath 214 and proximal end 232 of barb 228 protrudesthrough notch 220.

At the proximal end of insertion guide wire 210, core wire 212 extendsbeyond the proximal end 236 of core wire sheath 214 (see FIG. 29). Corewire 212 then passes through split sleeve 238 and the proximal end 240of core wire 212 is affixed, by any number of well known means, forexample, by use of adhesives, crimping, brazing or shrink fitting, to ashort section of proximal coil 242. Preferably, proximal coil 242 hasthe same inside and outside diameters as those of core wire sheath 214.Proximal coil 242 is provided, at its proximal end, with a rounded tip244.

Core sheath 214 may be comprised of coils of a biocompatible metal, forexample stainless steel, while core wire 212 is preferably asuperelastic alloy for example Nitinol and barb 228 is also preferablyNitinol or some other superelastic alloy.

The insertion wire 210 of this embodiment is inserted and used insubstantially the same manner as has been described with respect to theloop anchor embodiment. Release of the anchor mechanism, however,differs somewhat.

As noted earlier, insertion wire 210 is comprised of a core wire 212,core wire sheath 214 split sleeve 238 and proximal coil 242. Sheath 214,in addition to having a slit near the distal end, has a lumen 248 withinwhich core wire 212 is slidable. Since, the proximal end of core wire212, i.e., the end which is proximal of split sleeve 238, is affixed tocoil 242, core wire 212 can be made to slide axially within sheath 214by pushing on coil 242 while holding the medial portion of sheath 214.

Absent the application of axial force in the distal direction, splitsleeve 238 prevents core wire 212 from inadvertent distal movementwithin core wire sheath 214. When a physician applies distally directedforce on proximal coil 242, initially, split sleeve 238 resists suchforward movement of proximal coil 242. However, continued force appliedto coil 242 causes split sleeve 238 to buckle and separate along slit246 thereby permitting core wire 212 to move distally within core wiresheath 214.

After the guide sheath has been withdrawn, tension on the insertion wire210 is released and insertion wire 210 is advanced slightly further intothe artery, perhaps an additional 1-2 inches. Then, while wire sheath214 is held in one hand, coil 242 is pushed axially in the direction ofarrow R' (FIG. 29). This causes core wire 212 to slide distally throughsheath 214 pulling barb 228 with it until the proximal tip 232 of barb228 is inside lumen 248 of sheath 214 (FIG. 30), thus releasing theanchor and enabling insertion wire 210 to be withdrawn entirely from thecollagen plug. The guide sheath/canister/plunger assembly can then beremoved and discarded, leaving only the collagen plug in place.

FIG. 31 shows a second version of the barb embodiment of the subjectinvention. The insertion wire 300 of this embodiment is comprised of acore wire 302, similar to core wire 212 of the first embodiment, a corewire sheath 304, a tip 306 and soft-tipped barb 308. The core wiresheath 304 of this embodiment is made of a biocompatible plastic,preferably polyamide tubing. As in the first version of the barbembodiment, core wire 302 is preferably made of a superelastic alloy,for example, Nitinol.

Attached to the distal tip 306 of core wire 302 is coil 310 having adistal tip 322. In the normal, preinsertion state, the proximal portion312 of coil 310 is within lumen 314 of sheath 304.

Proximal to distal end 316, core wire sheath 304 is provided with slitor notch 318 which is sized to permit sliding passage therethrough ofsoft tipped barb 308. The distal portion of barb 308 is attached, forexample, by brazing or spot welding, to core wire 302 and the proximalend of barb 308 is provided with a flexible J-tip 320.

In order to permit retraction of barb 308, end 312 of coil 310 is sizedas to be slidable within lumen 314. Retraction of barb 308 isaccomplished by exerting axial force, in the distal direction, on corewire 302.

The proximal end (not shown) of insertion wire 300 is similar to theproximal end of insertion wire 210 of the first version of thisembodiment and the second version is used in the same way as the first.

FIGS. 32-34 depict a third version of the barb embodiment of the instantinvention. In this version, like the version of FIGS. 28 and 29, theinsertion guide wire 350 is comprised of a sheath 352, a core wire 354,a barb 356 and two safety wires 358 and 360. At its distal end, barb 356is connected to core wire 354 by a crimp and at its proximal end it isformed into J-tip 364.

Core wire sheath 352 of this embodiment is comprised of two separatesections, a distal section 352a and a proximal section 352b. Sections352a and 352b are both brazed to safety wires 358 and 360 with notch 368intervening between sections 352a and 352b. Although safety wire 360reaches essentially to the distal end of the guide wire, safety wire 358terminates at 366 just slightly past notch 368--just far enough past toensure a good brazed joint that will help support and position section352a.

It has been found that, because notch 368 is open around almost theentire circumference of core wire sheath 352, this embodiment of theinsertion guide wire can be inserted through the guide sheath and intothe artery with barb 356 fully retracted into the interior of section352a. This is accomplished by sliding core wire 354 distally relative tosheath 352 so that crimp 362 pulls barb 356 in a distal direction untilJ-tip 364 straightens out and enters fully into the interior of section352a. With the barb retracted, insertion guide wire 350 can be insertedthrough the procedural sheath without worrying about where in the arterythe tip of that sheath is. The procedural sheath is then withdrawn,leaving the insertion guide wire 350 in place. Next, after digitalpressure P is applied, guide wire 350 is slowly withdrawn until mark 374emerges at the skin line. The emergence of mark 374 is a signal to thephysician that barb 356 is in the vicinity of the arterial puncture andcan be deployed. Then, core wire 354 is pulled in the proximal directionand, because there is a residual curve in barb 356, as crimp 362 ispulled proximally, tip 370 finds notch 368 and exits therethrough. Crimp362 acts as a natural stop against the end 366 of safety wire 358 toprevent core wire 354 from being pulled too far in the proximaldirection. When it is time to retract the barb so it no longer acts asan anchor, the process is just reversed.

This version, as well as the fourth version of the barb embodimentdescribed below, is particularly well suited for a procedure whereinthere is potential for snagging on side branches. It can be insertedthrough the procedural sheath and into the artery with the barb 356fully retracted which is believed to be the preferred method ofinsertion. A marker (not shown) on the insertion wire 350 can beemployed to tell the physician that notch 368 has passed the tip of theprocedural sheath and has entered the artery. Then, both the insertionguide wire 350 and the procedural sheath can be withdrawn together untilthe tip of the procedural sheath is just slightly beyond the arterialpuncture as indicated by a mark (not shown) on the procedural sheath.Alternatively, the sheath can be withdrawn first, followed by withdrawalof guide wire 350 until mark 374 emerges at the skin line. Then, withfull assurance that there are no longer any side branches between notch368 and the arterial puncture, barb 356 can be deployed without fearthat it will hang up on a side branch.

A fourth version of the barb embodiment of the instant invention isdepicted in FIGS. 35-37. This fourth version is identical to the versionof FIGS. 32-34 except that in this fourth version the empty space in thenotch area between core wire 354 and barb 356 is filled with a plasticcompound 372. This plastic fill helps tip 370 find and exit throughnotch 368. Plastic fill 372 can also serve to support and hold sections352a and 352b in position but apart from one another. Plastic fill 372can serve this support function together with safety wires 358 and 360or instead of one or both of those.

The third embodiment of this invention is depicted in FIGS. 38-43. Inthis embodiment, the anchor is formed by starting with a standard guidewire in which the outer sheath is formed of a wire coil. The distal endis turned back upon itself to form a loop of greater than 360°. Wherethe coil overlaps itself, the coils are spread apart and the adjacentcoils interleaved. A core wire is used to lock those coils in thatinterleaved condition.

FIG. 38 shows the distal portion of an insertion guide 410 wireaccording to this embodiment in the process of being assembled.Insertion wire 410 is a modified standard guide wire comprised of asafety wire 412 and a wire coil sheath 414. Sheath 414 is comprised oftwo sections of coil wire, a main section 416 and a reverse section 418.Coil sections 416 and 418 are wound with opposite hand pitch. Forexample, main coil 416 could be wound with a right hand pitch andreverse coil 418 with a left hand pitch or vice versa. Sections 416 and418 are joined at 420 by conventional means, for example, by buttbrazing and each is preferably brazed over a distance of about 1/16"back from junction 420.

Main coil 416 may be comprised of a biocompatible metal, for examplestainless steel, and reverse coil 418 may be comprised of this same or adifferent biocompatible material, while safety wire 412 is preferablystainless steel.

The distal portion of insertion guide wire 410 is bent twice, once toform radius end 422 in main coil 416 and again to form opposite radiusend 424 in reverse coil 418, thereby producing an elongated loop 426having on overall arc of greater than 360°. In addition to having tworadius ends, loop 426 has two parallel sides 428 and 430 with coils 416and 418 being joined along parallel side 428. Parallel side 430, becauseloop 426 is greater than 360°, overlaps the main body of coil 416.

Running through lumen 432 of insertion guide wire 410 from proximal end443 is locking core wire 434 which has a proximal tip 436 and a distaltip 438 and which is bent over at its distal end to form hook 440. Thewidth W of hook 440 is sufficiently small so that it can slide easilywithin lumen 432.

At the proximal end of insertion guide wire 410, locking core wire 434extends beyond the proximal end 442 of wire coil sheath 414, throughsplit sleeve 444 into proximal coil 446. The proximal end 436 of corewire 434 is affixed, by any number of well known means, for example, byuse of adhesives, crimping, brazing or shrink fitting, to proximal coil446. Preferably, proximal coil 446 has the same inside and outsidediameters as those of wire coil sheath 414. Proximal coil 446 isprovided, at its proximal end, with a rounded tip 448.

In order to assemble the insertion guide wire, locking core wire 434 isinserted into lumen 432 of coil sheath 414 until tip 438 is distal oftip 462 of reverse coil 418. The coils of side 430 are then spread apartas are the coils of main section 416 which are adjacent side 430. Theadjacent spread coils are then pushed together so that they interleaveand locking core wire 434 is slid proximally so that hook 440 entersinto the space between the interleaved coils. The interleaved coils canthen be released since hook 440 is holding them in their interleavedcondition. By holding the adjacent coils interleaved, hook 440 maintainsloop 426 in the distal end of insertion guide wire 410.

Insertion and use of this embodiment is substantially as described abovewith respect to the first embodiment.

As noted earlier, insertion wire 410 is comprised of a locking core wire434, wire coil sheath 414, split sleeve 444 and proximal coil 446.Sheath 414 has a lumen 432 within which locking core wire 434 isslidable. Since the proximal end of core wire 434, i.e., the end whichis proximal of split sleeve 444, is affixed to coil 446, core wire 434can be made to slide axially within sheath 414 by pushing on coil 446while holding the medial portion of sheath 414.

Absent the application of axial force in the distal direction, splitsleeve 444 prevents core wire 434 from inadvertent distal movementwithin wire coil sheath 414. When a physician applies distally directedforce on proximal coil 446, initially, split sleeve 444 resists suchforward movement of proximal coil 446. However, continued force appliedto coil 446 causes split sleeve 444 to buckle and separate along itsslit thereby permitting core wire 434 to move distally within core wiresheath 414.

After the guide sheath has been withdrawn to a point just proximal tothe proximal end of the collagen plug, as described above, tension T isreleased and insertion wire 410 is advanced slightly further into theartery, perhaps an additional 1-2 inches. Then, while wire sheath 414 isheld in one hand, proximal coil 446 is pushed distally in the directionof arrow R" (FIG. 41) relative to sheath 414 until tip 438 at the end ofhook 440 passes out of between the interleaved coils. Those coils, onceno longer restrained by hook 440, separate and loop 426 opens. Theinsertion wire 410 is then pulled in a proximal direction. As the regionof junction 450 reaches the arterial puncture, the unrestrained coilseasily straighten out and guide wire 410 can exit without impediment.

While the subject matter of this invention has been described inconnection with several specific embodiments, it should be understoodthat numerous modifications could be made by persons of skill in thisart without departing from the inventive concept described herein.Accordingly, the above description is intended to be merely illustrativeand not limiting. The scope of the invention claimed should beunderstood as including all those alternatives, variants, modificationsand equivalents which the above specification would readily suggest orwhich would readily occur or be apparent to one skilled in the art uponreading the above.

What is claimed is:
 1. A guide wire, comprisinga sheath having alongitudinal axis, a proximal end, a distal end and a lumen extendingfrom said proximal end toward said distal end; an aperture formed in anintermediate portion of said sheath at a spaced distance from saiddistal end, said aperture delimiting a distal portion of said sheathbetween said distal end and said aperture; a core wire slideablyarranged in said sheath and having a proximal end and a distal end, saidcore wire being movable between a first position in which anintermediate portion of said core wire between said proximal and distalends protrudes from said sheath through said aperture to form a loop andsaid distal portion of said sheath forms an angle of less than about180° with a remaining portion of said sheath, said loop and said distalportion of said sheath in said first position of said core wire eachhaving a component projecting in a direction transverse to saidlongitudinal axis, and a second position in which said intermediateportion of said core wire is substantially entirely within said lumen ofsaid sheath, whereby movement of said core wire from said first positionto said second position eliminates said loop and moves said distal endof said sheath into substantial alignment with said longitudinal axis.2. The guide wire as claimed in claim 1, further comprising a referencemark for indicating a predetermined distance from said slit.
 3. Theguide wire as claimed in claim 1, further comprising a J-tip on saiddistal end of said sheath.
 4. The guide wire as claimed in claim 1,wherein said sheath is formed from a biocompatible material.
 5. Theguide wire as claimed in claim 4, wherein said sheath is formed frompolyethylene.
 6. The guide wire as claimed in claim 4, wherein saidsheath is formed from a metal coil.